1. Field of the Invention
The present invention relates to a sheet conveying apparatus that conveys sheets and an image forming apparatus such as a copying machine or a printer that uses the sheet conveying apparatus.
2. Description of Related Art
An example of a conventional sheet conveying apparatus is illustrated in FIG. 13. The sheet conveying apparatus reverses a sheet having an image formed on one side thereof, to discharge (back-side discharge) the sheet with the image side face down. Such discharging is performed to maintain the proper page order of sheets having images formed thereon.
Specifically, a conveying path is switched by a first switching member 24 rotating to a predetermined position and a sheet having an image fixed on the top side thereof by a fixer is conveyed to a first reversal path 51. The sheet is then caused to pass through a gate 53 where a flexible material 53S is provided, by a pair of carry-in rollers 52 and is conveyed to a second reversal path 54.
In this case, the sheet causes the flexible member 53S to bend by its toughness to pass through the gate 53. The flexible member 53S is affixed at its one end to the gate 53 and abuts at its other end on a guide plate 54G which composes the second reversal path 54.
Then, the conveying path is switched by rotating a second switching member 56 to a predetermined position and the sheet is conveyed to a third reversal path 57.
The sheet is further conveyed by a reversal roller 58 until a sheet trailing end reaches a reversal point A. The reversal roller 58 stops after a lapse of a predetermined period of time from when a reversal sensor 55 detects the sheet trailing end. The reversal roller 58 is driven by a forward/reverse rotatable stepping motor (not illustrated).
Thereafter, the reversal roller 58 is reversely rotated. At this time, a sheet leading end in a reversal direction is prevented from returning to the first reversal path 51 by the flexible member 53S affixed to the gate 53. The sheet passes through a pair of discharge rollers 59 and is discharged onto a discharge tray 27 by a pair of outer discharge rollers 26. By this, sheets are stacked on the discharge tray 27 with their image sides face down (see Japanese Patent Application Laid-Open No. 10-139248).
In Japanese Patent Application Laid-Open No. 10-139248, an image side of a subsequent sheet rubs against a previous sheet. In the sheet conveying apparatus, a sheet has been just fixed and thus it is highly likely that an image is not sufficiently dried. If the image side of the sheet is rubbed in such a state, the image may be significantly degraded.